Safety appliance.



F. Ross.

SAFETY APPLIANCE. APPLICATION FILED JUNE 22.1914.

1. 163,??? Patented Dec. 14, 1915.

4 SHEETS-SHEET 1'.

Max:772.

F. BOSS.

SAFETY APPLIANCE.

APPLICATION FILED JUNE 22.11914.

Patented new, 1915.

4 SHEETSSHEET 2.

F. ROSS.

SAFETY APPLIANCE.

APPLICATION FiLEl) JUNE-I22, 1914,

1 ,163,77%. Patented Dec. 14, 1915.

4 SHEETSSHEET 3.

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anon W13 F. ROSS.

SAFETY APPLIANCE. APPLICATION FILED JUNE 22. I914.

Patented Dec. 14, 1915.

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entra n snanns; PATENT OFFJIGE.

FRANK ROSS, OF CLEVELAND, OHIO, ASSIGNOR TO THE CLEVELAND FOUNDRY COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

SAFETY APPLIANCE.

Specification of i' Letters Patent.

Patented Dec. 1141, 1915.

To all whom it may concern:

Be it known that I, FRANK Ross, a citlzen of the United States, residing at Cleveland,-

in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in Safety Appliances, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings.

This invention relates to safety appliances that are especially adapted for use with heavy power presses, such as draw-presses; and it has for its general object the provision of a device that will prevent an operator from reaching the work that he has .placed between the dies, after the clutch operating mechanism has been actuated, until the operation of the press \has been completed.

It is well known to those familiar with the art to which this invention relates, that presses of the aforesaid character are comparatively slow of action; that is to say, there is enough time between the actuation of the clutch operating mechanism and the engagement of the upper die member with the Work, to tempt the operator to straighten the work, should it have been placed in the press slightly out of position. Even though efforts have been made to prevent this practice by providing clutch operating means that requires the simultaneous use of both hands to effect its actuation, many injuries have been suffered because of the lag in the operation of the press.

Therefore, it is a further object of this invention to provide a safety appliance for presses of the aforesaid class that will intercept the path of movement of the operators hands, as he reaches toward the dies, which appliance will be operated by the same medium as that employedfor actuating the clutch operating mechanism, andwhich will become effective to guard the operator against injury, before the clutch operating mechanism is actuated. To this end 1 provide the safety appliance set forth in theannexed claims, and an embodiment of which is illustrated in the accompanying drawings forming a part hereof, whe1'ein Figure 1 is-a front elevation of a press having the safety appliance of my invention 1 applied thereto; Fig. 2 is a side elevation of the press, the gear wheels whereof are removed to more clearly show certain parts of the mechanism (the out-lines of the large gear being indicated by dotted lines, and the shafts shown in se ion) Fig. 3 is an elevation of a portion 0 the opposite endof the press to that shown in Fig. 2; Fig. .4: is a front elevation of the gate-latch operating cylinder; Fig. 5 is a central, vertical, longitudinal section thereof; Fig. 6 is a plan view of the cylinder through which the clutch operating mechanism is actuated; Fig. 7 is a central, vertical section thereof; Figs. 8 and 9 are respectively a plan and a central, vertical section of one of the pressure fluid valves; Fig. 10 is an enlargement of the upper portion of Fig. 2 and shows the mechanism in another phase of its operation; Fig. 11 is a sectional detail on line 111l of Fig. 1; and

- Fig. 12 is a diagram of electrical means for actuating the safety appliance and the clutch operating mechanism.

In the drawings I have shown a press of standard design which comprises a base 1 that is supported a suitable distance above the floor by legs 2, and from either end of which rises one of the side members 3 that are connected at their upper end by a beam 4:. pair of brackets 5 depend from the central portion of the beam 4, and within these brackets and the upper ends of the side members 3 is journaled a crank shaft 6 which carries at one of its ends a gear 7, and at its opposite end a crank disk 8. The cranks 9 of the shaft, are connected to the head 10 by the connecting rods 11. At 12 and 13 are shown the upper and lower dies, respectively. Journaled within the brackets 1 that exthe driving shaft 15 that is adapted to be continually driven through the belt pulley 16, a fly wheel '17 being fixed to the shaft adjacent the pulley 16. Just outside of the right hand side member 3 of the press (as it is viewed from the front or feeding side, as in Fig. 1), the driving shaft 15 has loosely mounted upon it a pinion 18 that carries one of the clutch members 19. The complemen- (tend from the rear of the side members 3 is tary clutch member 20 is splined upon the end-of the driving shaft 15 and has an extension to which is swiveled the shifting fork 21, through asplit collar 22, in accordance with the usual practice.

While I have shown and described a clutch of the dental type, it will be understood that any approved style may be employed such, for instance, as a friction clutch.

The fork 21 is carried by the end of a slide rod 23 that is guided through the boss 24 which projects from the side of the bracket 25, said bracket being attached to the right hand side member 3, and w1th1n this same bracket is journaled a rock shaft 26 that has an arm 27 fixed to its forward end, the upper end of the arm 27 be ng bifurcated and slotted for connection with the end of the slide rod 23. On the opposite side of the bracket 25 the rock shaft 26 has fixed to it a rocker arm 28 which has a circular head 29 that is confined within a slot 30 in a post 31.

The post 31 is capable of a slight vertical movement and, as will appear clearly from Figs. 1 and 2, its lower end is guided within a bracket 32 that is secured to the side of the base 1; and the downward movement of the post 31 is limited by a collar 33 that is adapted to engage the upper surface of the bracket 32. Figs. 2 and 10 show the upper end of the post 31 as provided with an ad-- justable extension 34 which telescopes within the socketed lower end of the pendant 35.

The pendant 35 is hung from the free end of an arm 36 which is pivoted at 37 to an extension 38 which projects from the upper forward corner of the right hand side member 3. The arm 36 is provided with an antifriction roller 39 which rides upon a cam 40 that is keyed to the crank shaft 6 be tween the gear 7' and the adjacent side member 3. Journale'd between a pair of ears 41 that extend from the forward side of the pendant 35 is a dog 42, the nose 43 of which projects through a slot 44 in the side of the pendant and is arranged to enter a notch 45 in the upper end of the extension 34.- The lower end of the dog 42 is connected by a link 46 to the vertical arm 47 of a bell crank 48 that is mounted upon a stud 49 that projects from the side member 3. A spring 50, which has one of its ends anchored to the stud 49 and its opposite end secured to the pin 51 that connects the adjacent ends of the links 46 and the dog 42, tends to swing the dog so that its nose 43 will be present in the.direction of the notch 45, at the same time rocking the bell crank ing the clutch operating mechanism will be described later, but at this time I wish rocked upon its pivot through the links 46 to withdraw its nose 43 from the notch 45 in the extension 34, so that the post 31 will drop by gravity until it is stopped by the engagement of its collar 33 with the bracket 32. During its drop, the post 31 carries the free end of the rocker arm 28 with it, so

as to oscillate the rock shaft 26 and swing the arm 27 in a direction to draw the slide rod 22 and the shifting fork 21 in the direction to move the clutch member 20'into engagement with the clutch member 19. At this instant the gear 7 is started rotating, and with it the crank shaft 6. During the rotation of the crank shaft 6, the arm 36 will be lowered by reason of the eccentricity of the cam 40 (the roller 39 normally resting upon the high portion of the cam) and the pendant 35 lowered over the extension 34 of the post 31 until the nose 43 of the dog 42 snaps into the notch 45 of the aforesaid extension, under the influence of the spring 50. Throughout the remainder v of the complete rotation of the shaft 6, the cam 40 elevates the arm 36 to its former or idle position, and now that the post 31 is connected to the pendant 35, the post is elevated to oscillate the rocker arm 28, the shaft 26 and the arm 27' in a direction opposite to that previously described, which results in the slide rod 23 and the .fork 21 being shifted in a direction to disengage the clutch members. The parts so far described constitutethe draw press, and form no part of my invention except as they enter broadly into the combination expressed by erably made'of a heavy wire screen that is supported between the longitudinal frame members 57 which have their corresponding ends connected by sleeves 58 that are slidable upon the guide rods 55. Each of the sleeves 58 has a rearward projection 59 near its upper end which is adapted to be engaged by one of the latch hooks 60 that is secured to a rock shaft 61, near one of its ends, the extreme ends of the rock shaft 61 being journaled within bosses 62 which extend transversely of'sleeves 63 that are slidable upon the guide rods 55, above the former sleeves 58. Near its right hand end, the. shaft 61 has fixed to it a rocker arm 64. A rock shaft 65 is journaled within blocks 66 that are supported within the crotch of the l.shaped brackets 53, and this shaft is oscillated during the rotation .of the crank v shaft 6 through the connecting link 67 which has one of its ends connected to the crank pin 68 of the disk 8, and its opposite end to the free end of a rocker arm69 that is secured to the left hand end of the rock shaft 65. Just inside the brackets 53, the rock shaft 65 has fixed to it a pair'of arms 70 'within the bifurcated, forward end of which are pivoted the upper ends of links 71 which latch hooks 60, its rocker arm 64 and sleeves 63, will be lowered and then raised again to the position shown inthe drawings.

In Figs. 4 and 5 I have shown in detail- 72, that is supporta pressure fluid cylinder ed by the right hand side member 3 in such a position as to cause its piston rod 73 to project toward the rocker arm 74 when the rock shaft 61 is in its elevated position. Projecting from the rear end of the cylinder 72, and with, is a supporting plate 7 1 through which the cylinder has connection with the side member 3.

A cylindrical, hollow boss 75 extends along one side of the supporting plate 7 1, and the bore 76 thereof has communication with the interior of the cylinder at 77. The rear end of the bore 7 6is tapped at 78 for the application of a supply pipe. At about its longitudinal center, an outlet-port 79 is formed in the side wall of -the cylinder,'and an internally threaded boss 80, which projects from said side wall and with which the port 79 communicates, provides'a connection for a suitable conduit. The piston is shown at 8 1, and its rod 73 projects forwardly through a cap 82 which screws into the end of the cylinder, and which is counterbored at 83 for the accommodation of a spring 8 1 that is confined between the end of the counterbored portion of the cap 82 and the forward face of the piston 81,

whereby said piston is normally held against the rear'end of the cylinder.

At a suitable distance below the bell crank 48, a bracket 85 is secured to the right hand side member 3 and supports a pressure fluid cylinder 86 in a position to cause its piston rod 87 to be projected toward the horizontal branch 52 of the bell crank 18. A clear understanding of the construction of the cylinder 86 may be had from an inspection of Figs. 6 and 7. The cylinder 86 is secured to the bracket 85' by cap screws 88, and at its lower end, the cylinder is provided with an internally threaded boss .89, for the reception of a pressure fluid pipe which communicates with the interior of the cylinder through the port 90. The upper end of the cylinder preferably formed integral there-.

valves 107 and 108.

closed by a head 91 that is secured in place by the cap screws 92, and extending upwardly from the head 91 is a neck 93 that is bored at 94 for the guidance of the piston rod 87, and is counterbored at 95 for the reception of a spring 96. About the lower end of the neck 93', the head 91 is provided with a series of exhaust ports 97. A piston is shown at 98 which consists ofa cylindrical block having a central recess that extends downwardly from its upper end for the reception of the lower end of the piston rod 87, the same being secured therein by the pin 99. A series of air ports 100 extend longitudinally through the piston 98,

. and they are spaced a slight distance in from the periphery thereof. Two bores 101 (although there might be any desired number of them) which are somewhat larger than the ports 100, extend in the same direction through the piston as the aforesaid bores, and serve as guides for the rods 102 which are threaded at 103 into a circular valve-plate 104: that is arranged to bear against the lower end ofthe piston. It will be observed from Fig. 7, that the valve plate 104 is of lesser diameter than the piston 98. The spring 96 acts to retain the parts in the position shown in Fig. 7.

A'pressure fluid pipe 105 passes in front of the press at a convenient elevation to be reached by the hands of the operator, and forward of the right hand side member 3, the pipe turns inward and then upward to where it has connection with the cylinder 72 through the bore 76 of the boss 75. A second pipe 106 connects the outlet port 79 of the cylinder 7 2, with the inlet port 90 of the cylinder 86. WVhere the pipe 105 passes in front of the press, it is provided with two These valves may be identical, but since the pressure of the fluid is constantly against the valve 107, it is desirable to use a very substantially constructed valve and one that is positive in its action, and for that reason I employ the valve shown in detail in Figs. 8 and 9, which isof standard make and forms no part of my 1nvention. The valve 108 is of the type that isseated by a spring and operated by the depression of its valve stem 109, by the lever 110. Returning now to, valve 107, it W111 be observed from the aforesaid figures, that said valve comprises a casing to which-the reference numeral 107 is applied, and that is formed from a block of metal that has a central bore, the. upper portion of which is of a size to form a guide for the valve stem 111, and the lower portion of which is somewhat larger than the valve cap 112, the cen- -tral portion of the bore being reduced some- .a transverse groove into which projects the upper end of the valve stem 111, and to one vside of the valve stem, the operating lever 115 is pivoted at 116 and normally lies over the stem of tnc valve 111. At no time is the upper end of thevalve stem 111 above the top plane of the valve casing. The upper portion of the valve 108 is formed in like manner, for a purpose which will be brought out hereinafter.

In taking up a description of the operation of the safety appliance, let us assume that the parts are in the position shown in Figs. 1 and 2, with the gate 56 elevated and supported by the engagement of the latch hooks, 60 with the projections 59 of the sleeves 58, that form the ends of said gate. Now, after the operator has placed a blank between the dies of the press, he depresses the operating levers 115 and 110 of the valves 107 and 108, respectively, whereupon the pressure fluid is permitted to pass through the pipes 105 to the rear end of the cylinder 72, and acting upon the rear face of the piston 81, forces said piston toward the forward end of the cylinder against the tension of the spring 83. As the piston rod 7 3 is ejected, it strikes the upper end of the rockerarm Y64 and rocks the shaft 61 in a direction to withdraw the latch hooks 60' from the projections 59, thereby allowing the gate 56 to drop by gravity until its descent is arrested by the engagement of the sleeves 58 with the brackets 54. With the gate in its lower position, the operator is prevented from reaching his work until the press has made a complete operation and the gate has been restored to its upper position, as will be clearly explained later on in this description. When the piston 81 reaches the forward end of the cylinder 72, it throws the port 7 9 into communication with the rear end of the cylinder, thereby permitting the pressure fiuid to flow on through pipe 106 to the lower end of the cylinder 86. Acting upon the underneath surface of the -valve-plate 104, the pressurefluid elevates the piston 98 against the tension of the spring 96, thereby projecting its piston rod 87 upward into contact with the horizontal branch 52 of the bell crank 48. During a complete movement of the piston 98, the bell crank 48 is given a sufficient angular movement to disconnect the dog 42 from the extension of the post 31, and cause an operation of the press as previously described. As the piston 98 approaches the upper end of its stroke, the upper end of the rods 102 contact with the head 91. Therefore the progress of the valve-plate 104 is arrested and a slight separation between said plate and the lower end of the piston 98 is effected. As soon as this occurs, the pressure fluid which has been imprisoned beneath the piston, escapes about the edge of the valve-plate and through the ports 100 to the upper end of the cylinder, from where it passes to the atmosphere through the exhaust ports 97. Ofcourse, in actual practice,.the valve-plate 104 drops directly to the bottom of the cylinder as soon as the upper ends of its rod 102 contact with the head 91, and almostimmediately the piston 98 is forced to the bottom of the. cylinder by the spring 96.

From this description it will be seen that just as soon as the valves 107 and 108 are simultaneously operated, the gate 56 will drop to its safety position; and not until said gate is released will the pressure fluid be permitted to pass on to the cylinder 86 to effect the actuation of the clutch operating mechanism. When the clutch has I been actuated, the press will operate and the crank 6 willmake a complete rotation, during which time the rock shaft 65 will be oscillated to lower. and elevate the rock shaft 61, the latch hooks 60 snapping over the a projections 59 of the sleeves 58 of the gate and causing said gate to be elevated.

I In dotted lines in Fig. 1, the operating levers of the Valves 107 and 108 are shown in the position they should occupy when the press is not in use, and especially when the dies are being changed; for, with the levers in such position, there is no danger of the valves being accidentally actuated from something striking or fallin upon them. It will be remembered also, that the upper end of each valve stem is protected by the portions of the casing that extend upward on both sides thereof.

While I have referred to the safety appliance actuating means, and the actuating means forthe clutch operatin being operated by a pressure uid, it is obvious that other mediums might be .employed for thesame purpose, such, for instance, as electricity; so in Fig. 11 I have shown a diagram involving certain of the parts of the mechanism and substituting solenoids for the cylinders 72 and 86, and I have substituted switches for the valves 107 and 108 through the simultaneous operamechanism,

'tion of both of which the energization of character described, of press operating mechanism, a safety gate that is movable into and out of safety position, gate controlling mechanisni whereby said gate is permitted to move into safety position and.

' a carrier for said gate, a latch-whereby the gate may be connected to the carrier, the carrier normally supporting the gate in ineffective position, means for first operating the latch to cause it to release the gate, said means thereafter effecting an actuation of the press operating mechanism, and connections whereby the operation of the press will move the carrier into proximity to the gate and cause it to carry the gate to ineffective position.

3. The combination with a press of the character described, of a clutch, clutch operating mechanism, a guide, a safety gate movable along said guide from normal to Y safety position, a gate carrier that is also movable along the guide, means whereby the gate may be connected to the carrier, further means for first rendering such connecting means ineflective whereby the gate is permitted to move to safety position and which then actuates the clutch operated mechanism, and connections through which the operation of the press will move the gate carrier to cause it to pick up the gate through the aforesaid connections and return it to normal position. a

4. The combination with a press of the character set forth, of press operating mechanism, a guide, a gravity safety gate that is movable along said guide, a gate carrier that is also movable along the guide. a latch forconnecting the gate to the carrier, the gatecarrier normally suspending the gate in in-' effective position, means for first operating the latch to release the gate, and then actu-; ating the press operating mechanism, and connections for moving the carrier along the guide to pick up said gate through the aforesaid latch and return it to normal position as the press is operated.

5. The combination with a press having a main operating shaft, of a. clutch through which said shaft is rotated, clutch operating mechanism, a guide, a gravity safety gate movable along said guide, a gate carrier also movable along the guide, a latch for con necting the gate to the carrier, the carrier normally supporting the gate in ineffective character described,

to permit the gate to fall to safety position and then actuating the clutch operating mechanism, and connections between the main shaft of the press and the gate carrier whereby the rotation of said shaft will move the gate carrier toward the gate, and cause 1t to return the gate to normal position.

6. The combination with a press of the character described, of press operating mechanism, a safety gate that is movable into and out of safety position, mechanism controlling the ,movement'of the safety gate, a current actuate device for operating said controlling mechanism, a second current operated device for actuating the press op-.- erating mechanism, and means for supplying current to the first and to the second of said devices in sequence.

7. The combination with a press of the character described, of press operating mechanism, a safety gate that is movable into and out of safety position, mechanism controlling the movement of the safety gate, a current actuated device for operating said controlling mechanism, a secondcurrent operated .device for actuating the press operating mechanism, conductors for supplying current to said devices, and means for preventing the flow of currentto the second device until the first device has been actuate 8. The combination with a press of the of press operating mechanism, a safety gate that is movable into and out of safety position, mechanism controlling the movement of thevsafety gate, a current actuated device-for operating said controlling mechanism, a second current operated device for actuating the press operating mechanism. conductors for supplying current to said devices, and means controlled by the first device for preventing the flow of current to the second device until the first device has been actuated.

9. The combination with a press of the character described, of press operating mechanism, a safety gate that is movable into and out of safety position, mechanism controlling the movement of the safety gate, current actuated means for first operating said controlling mechanism and then actuating the press operating mechanism, a conductor for supplying current to said means, two devices for interrupting the flow of current through said conductor, and operating a means for each device that is remote from trolling mechanism, said cylinder having an inlet port and an outlet port, the latter being located forward of the normal position of the piston, a second pressure fluid cylinder having a piston that is operatively connected to the press operating mechanism, a pressure fluid conduit which has connection with the inlet port of the first mentioned cylinder, a second pressure fluid conduit through which the outlet port of the first mentioned cylinder communicates with the second cylinder, and means for controlling the flow of pressure fluid through the first mentioned conduit.

11. In a safety appliance for presses of the character set forth, the combination of a gate having a sleeve at each of its ends, rods Whereon said sleeves are guided, a gate carrier having sleeves that are guided upon the same rods, a rock shaft that is supported by said carrier, a latch hook secured to said rock shaft near each of its ends, the sleeves of the gate having projections wherewith said latch hooks cooperate, means for oscillating the rock shaft, and connections between the operating shaft of the press and the gate carrier whereby said gate carrier will be caused to reciprocate upon the guide rods as the operating shaft is rotated.

In testimony whereof, I hereunto affix my- 30 of two witnesses.

FRANK ROSS.

signature in the presence 'W-itnesses:

W. E. SHEPPARD, S. S. CHADWICK. 

